In general, a conventional fluid flow type dyeing machine generates dye jets by means of jet nozzles or other devices to force the dye fluid and the object to be dyed to circulate and dyed in a high temperature, high pressure condition. The conventional dyeing machines has two categories, high temperature, high pressure type and room temperature, atmosphere pressure type. The conventional fluid flow type dyeing machine comprises a closed dyeing bath, a fabric guiding wheel, a jet nozzle, a fluid flow tube, a heat exchanger for temperature control and a dye circulation pump wherein, except in the rotary type dyeing machines, the fluid flow tube is in general disposed above the dyeing bath along the axial direction thereof with the jet nozzle located at the front end of the inlet opening of the fluid flow tube, the fluid flow tube being connected to the ends of the dyeing bath with the front and rear ends thereof, the fabric guiding wheel escorting the object to be dyed in the front end of the dyeing bath to approach the jet nozzle during the operation of the dyeing machine so as to allow the fluid flow formed by the dye jet from the jet nozzle or other means to force the dye fluid and the object to be dyed to move through the fluid flow tube to enter the rear end of the dyeing bath, the dye and the object to be dyed within the dyeing bath being driven forward by the dye flow that is sucked into the circulation pump from the front bottom side of the dyeing bath so as to circulate and conduct dyeing at the same time, the dye flow that enters the circulation pump being forced by the circulation pump to flow through the heat exchanger to increase or decrease the temperature thereof and then transmitted to the jet nozzle to form dye jet. Such a fluid flow dyeing machine, as shown in FIG. 1, comprises in general a closed dyeing bath 1 and a fluid flow tube 2. The fluid flow tube 2 has mounted at an end thereof a jet nozzle 20 and an opposite end thereof in fluid communication with the dyeing bath 1, the tube 2 being disposed in an inclined manner to help the dye inside the fluid flow tube 2 to flow back to the dyeing bath 1. The dye inside the dyeing bath 1 is forced toward the jet nozzle by means of a circulation pump so as to form fluid flow and to provide higher concentration dye fluid. When the object to be dyed 22 enters the fluid flow tube 2 through the end thereof that has the jet nozzle 20 mounted thereon, the jet nozzle 2 sprays dye to the object 22 which will then move through the fluid flow tube 2 by the impulsive force of the dye jet from the jet nozzle and the inclination of the fluid flow tube back into the dyeing bath 1 to dip into dye fluid and then escorted by the fabric guiding wheel 12 toward the jet nozzle 20 to be cyclically and repeatedly dyed. Since the movement of the object to be dyed 22, namely the moving speed thereof, is controlled by the dye jet provided by the jet nozzle 20 which drives the object to be dyed 22 to move forward, the jet nozzle 20 must has a great jet impulse for moving the object to be dyed 22. However, a jet impulse that is great will tend to damage the regularity of fiber arrangement of the fabric and the great jet impulse usually causes the formation of small "fiber balls" on the surface of the object to be dyed 22. This deteriorates the quality of the dyed fabric. On the other hand, reducing the jet impulse leads in insufficient penetration of the dye into the fabric and slowing down the movement of the object to be dyed which sometimes causes an out-of-phase condition between the fabric guiding wheel 12 and the jet nozzle 20 and thus leading in stop and accumulation of the object to be dyed which forces the machine to be shut down and thus lowering the productivity. Besides, since in such a conventional dyeing machine, the dye is only sprayed to the object to be dyed once by means of the jet nozzle 20, it takes longer time to sufficiently dye the object and the dyeing effectiveness thereof is not good enough.
Due to the above disadvantages, it is desirable to provide a fluid flow type dyeing apparatus which overcomes the deficiencies of the conventional devices, not only enhancing the quality of the dyed fabric, but also heightening the dyeing efficiency.